Collaborative Proposal: Fast Dynamos in the Computer, the Galaxy and theLaboratory

这个研究项目旨在了解天体物理磁场的产生和演化。磁场在许多天体物理过程中起着决定性的作用，从在无处不在的吸积盘中介导恒星形成和传递角动量到影响星系团内的加热/冷却。在所有这些情况下，流的大磁雷诺数要求磁场拓扑的任何变化都需要通过快速重连来实现，而磁场的产生则需要快速的发电机。该项目利用数值能力的最新进展来测试快速重连接和快速发电机的最新先进理论。它还提出了重联理论的进一步发展，与液态钠测量的理论和数值结果的比较，以及星系发电机的模拟。这项工作的另一个非常重要的成果将是开发一个平行的AMR MI-ID代码RIEMANN，用于模拟旋转天体物理系统中的MHD现象。这将是一个通用的实用程序，将广泛提供给社区。本项目由美国国家科学基金会星系外天文学和宇宙学项目（AST/EXC）资助

AST 0132246BalsaraThis research program is aimed at understanding the generation and evolution of astrophysical magnetic fields. Magnetic fields play decisive role in many astrophysical processes from mediating star formation and transporting angular momentum in ubiquitous accretion disks to influencing heating/cooling within clusters of galaxies. In all these situations, the large magnetic Reynolds numbers of the flows require that any changes of magnetic field topology be implemented through fast reconnection, while magnetic field generation requires fast dynamo.The project makes use of recent advances in numerical capabilities to test recently advanced theories of fast reconnection and fast dynamos. It also proposes further development of reconnection theory, comparisons of theoretical and numerical results with liquid sodium measurements, and simulations of the galactic dynamo. Another very important outcome of this effort will be the development of a parallel AMR MI-ID code, RIEMANN, for simulating MHD phenomena in rotating astrophysical systems. This will be a general-purpose utility that will be made widely available to the community. Funding for this project was provided by the NSF program for Extragalactic Astronomy & Cosmology (AST/EXC).***